巧笑倩兮"編輯上傳提供，詞條屬于開放詞條，當前頁面所展示的百科詞條介紹涉及宣傳內容屬于注冊用戶個人編輯行為。與四川盆地的所屬企業/主題/所有人主體無關，詞條主體可以提供資料認證申請管理本詞條權限免費更新資料，也可以因內容與實際情況不符快速在線向網站提出反饋修改！ 反饋
四(si)川盆地(di)聚居著四(si)川省和重(zhong)慶市大部分(fen)人(ren)口(kou)、居民(min)主要為漢族巴(ba)蜀民(min)系。是中國和世界上人(ren)口(kou)最多(duo)的區域之一。
中國著名(ming)紅層(ceng)盆地(di)(di)，中國各(ge)大盆地(di)(di)中形(xing)態最(zui)(zui)典型(xing)、緯度最(zui)(zui)南、海(hai)拔(ba)最(zui)(zui)低的盆地(di)(di)。位于長江上(shang)游地(di)(di)區，海(hai)拔(ba)500米左右，長江把它和東(dong)海(hai)一脈相(xiang)連(lian)，它是中國最(zui)(zui)大的外(wai)流(liu)盆地(di)(di)。
四(si)(si)川盆(pen)(pen)(pen)(pen)地(di)(di)(di)(di)的(de)(de)面(mian)(mian)(mian)積(ji)(ji)約26萬(wan)余平(ping)(ping)(ping)方(fang)千(qian)米(mi)（面(mian)(mian)(mian)積(ji)(ji)是(shi)居第五第六位的(de)(de)兩(liang)湖(hu)盆(pen)(pen)(pen)(pen)地(di)(di)(di)(di)和(he)銀額盆(pen)(pen)(pen)(pen)地(di)(di)(di)(di)的(de)(de)兩(liang)倍(bei)），占四(si)(si)川省面(mian)(mian)(mian)積(ji)(ji)的(de)(de)46%。四(si)(si)川盆(pen)(pen)(pen)(pen)地(di)(di)(di)(di)西(xi)(xi)(xi)依(yi)青藏高(gao)原(yuan)和(he)橫斷山脈，北(bei)(bei)近秦巴山脈，與(yu)漢中(zhong)盆(pen)(pen)(pen)(pen)地(di)(di)(di)(di)相望(wang)，東(dong)接湘鄂西(xi)(xi)(xi)山地(di)(di)(di)(di)，南(nan)(nan)連云貴高(gao)原(yuan)，盆(pen)(pen)(pen)(pen)地(di)(di)(di)(di)北(bei)(bei)緣(yuan)(yuan)米(mi)倉山，南(nan)(nan)緣(yuan)(yuan)大婁山，東(dong)緣(yuan)(yuan)巫(wu)山，西(xi)(xi)(xi)緣(yuan)(yuan)邛崍(lai)山，西(xi)(xi)(xi)北(bei)(bei)邊緣(yuan)(yuan)龍門山，東(dong)北(bei)(bei)邊緣(yuan)(yuan)大巴山，西(xi)(xi)(xi)南(nan)(nan)邊緣(yuan)(yuan)大涼山，東(dong)南(nan)(nan)邊緣(yuan)(yuan)相望(wang)于武陵山。這(zhe)里(li)的(de)(de)巖(yan)石，主要由紫紅(hong)色(se)砂巖(yan)和(he)頁巖(yan)組成(cheng)。這(zhe)兩(liang)種巖(yan)石極易風化發育成(cheng)紫色(se)土。紫色(se)土含(han)有豐富的(de)(de)鈣(gai)、磷(lin)、鉀等營養(yang)元素(su)，是(shi)南(nan)(nan)方(fang)最肥(fei)沃的(de)(de)自然土壤。四(si)(si)川盆(pen)(pen)(pen)(pen)地(di)(di)(di)(di)是(shi)全國紫色(se)土分(fen)布(bu)最集(ji)中(zhong)的(de)(de)地(di)(di)(di)(di)方(fang)，向(xiang)有“紫色(se)盆(pen)(pen)(pen)(pen)地(di)(di)(di)(di)”的(de)(de)美稱。四(si)(si)川盆(pen)(pen)(pen)(pen)地(di)(di)(di)(di)底部面(mian)(mian)(mian)積(ji)(ji)約16萬(wan)多平(ping)(ping)(ping)方(fang)千(qian)米(mi)，按其(qi)地(di)(di)(di)(di)理差異(yi)，自西(xi)(xi)(xi)向(xiang)東(dong)又可分(fen)為成(cheng)都(dou)平(ping)(ping)(ping)原(yuan)、川中(zhong)丘陵和(he)川東(dong)平(ping)(ping)(ping)行嶺谷三部分(fen)。成(cheng)都(dou)平(ping)(ping)(ping)原(yuan)西(xi)(xi)(xi)方(fang)是(shi)龍門山脈，東(dong)方(fang)是(shi)龍泉山脈。
四川(chuan)盆地(di)可明顯分為邊(bian)(bian)緣山(shan)地(di)和盆地(di)底部(bu)(bu)兩大部(bu)(bu)分，其(qi)面積(ji)分別約(yue)為10萬多(duo)和16多(duo)萬平(ping)方公(gong)里。邊(bian)(bian)緣山(shan)地(di)多(duo)中山(shan)和低山(shan)。
景觀各(ge)要素過渡性明顯，如(ru)動植物(wu)組成上(shang)(shang)分(fen)別滲透了華中區(qu)、西(xi)南區(qu)、青(qing)藏(zang)高(gao)原區(qu)和華北區(qu)的(de)成分(fen)。邊(bian)緣(yuan)山(shan)地(di)(di)(di)區(qu)從下而上(shang)(shang)一般具有(you)2～5個垂直自然分(fen)帶(dai)。邊(bian)緣(yuan)山(shan)地(di)(di)(di)是四川多(duo)種(zhong)經(jing)濟林(lin)木和用材林(lin)基地(di)(di)(di)。農業上(shang)(shang)水土流失較為嚴重。盆(pen)地(di)(di)(di)底部多(duo)丘陵、低(di)山(shan)和平原。地(di)(di)(di)表組成物(wu)質新而單一，多(duo)砂泥巖與第四紀沉(chen)積物(wu)。氣候上(shang)(shang)屬中亞熱(re)帶(dai)，熱(re)量遠比邊(bian)緣(yuan)山(shan)地(di)(di)(di)為高(gao)，但降水量不及邊(bian)緣(yuan)山(shan)地(di)(di)(di)。植被為人工的(de)次生林(lin)木所(suo)代替(ti)，覆被率低(di)，耕地(di)(di)(di)連片，夏伏旱和洪澇是這一地(di)(di)(di)區(qu)最(zui)大災害。
盆(pen)地(di)內(nei)部地(di)形地(di)貌(mao)顯(xian)示出明顯(xian)的三分特點(dian)，即盆(pen)西平原地(di)貌(mao)、盆(pen)中(zhong)丘陵地(di)貌(mao)和(he)盆(pen)東山(shan)地(di)地(di)貌(mao)，三者以龍泉山(shan)和(he)華鎣(ying)山(shan)為界。
四(si)川(chuan)盆(pen)地其輪廓(kuo)形(xing)(xing)態總體近似長方形(xing)(xing)，形(xing)(xing)似信封(feng)狀，右傾斜置在亞洲大陸(lu)，因(yin)此被地理學(xue)者稱之為信封(feng)盆(pen)地。信封(feng)盆(pen)地東部(bu)頂(ding)點(dian)(dian)云陽(yang)（靠近萬州(zhou)），南部(bu)頂(ding)點(dian)(dian)敘永(靠近遵義)，西部(bu)頂(ding)點(dian)(dian)雅安，北部(bu)頂(ding)點(dian)(dian)廣元。信封(feng)盆(pen)地幾(ji)何中(zhong)心(xin)城市遂寧（幾(ji)何中(zhong)心(xin)點(dian)(dian)大致在蓬溪南部(bu)地區），中(zhong)北部(bu)（內(nei)頂(ding)角(jiao)）中(zhong)心(xin)城市南充，中(zhong)南部(bu)內(nei)頂(ding)角(jiao)安岳。
四川盆(pen)地西部的成都和東南部的重慶皆為國家中(zhong)心城市。
四川盆(pen)地(di)由盆(pen)周山(shan)地(di)和盆(pen)地(di)底部構(gou)成。
盆(pen)周(zhou)東部為長江(jiang)三峽(xia)，南部為云貴高原，西部為青藏高原，北部為大(da)巴山。
盆地底(di)部(bu)主(zhu)要分為(wei)川(chuan)東平(ping)(ping)行(xing)嶺谷、川(chuan)中丘(qiu)陵和川(chuan)西成都平(ping)(ping)原三(san)部(bu)分。龍泉山(shan)是成都平(ping)(ping)原和川(chuan)中丘(qiu)陵的界(jie)山(shan)，華(hua)鎣山(shan)是川(chuan)中丘(qiu)陵和川(chuan)東平(ping)(ping)行(xing)嶺谷的界(jie)山(shan)。
（1）在龍泉山(shan)和龍門(men)山(shan)、邛(qiong)崍山(shan)之間的盆西(xi)平原(yuan)(yuan)，系(xi)斷裂下(xia)陷(xian)由岷江(jiang)水系(xi)的河(he)流(liu)沖積(ji)(ji)而(er)成(cheng)，面積(ji)(ji)約8000平方千米，為我國西(xi)南最(zui)大的平原(yuan)(yuan)，因成(cheng)都(dou)(dou)(dou)位于平原(yuan)(yuan)之中， 故稱成(cheng)都(dou)(dou)(dou)平原(yuan)(yuan)。成(cheng)都(dou)(dou)(dou)平原(yuan)(yuan)海拔460米～750米，地勢由西(xi)北向東南傾斜，地表(biao)平坦(tan)，相對高差一般(ban)不超過30米～50米，它由岷江(jiang)、沱江(jiang)、涪(fu)江(jiang)、青衣江(jiang)等八(ba)條河(he)流(liu)沖積(ji)(ji)聯(lian)綴而(er)成(cheng)，土壤肥沃(wo)，河(he)渠稠密，有著名的都(dou)(dou)(dou)江(jiang)堰自(zi)流(liu)灌溉，自(zi)古以來素有“天府”之稱。
（2）在龍泉山(shan)和華(hua)鎣山(shan)之間的盆中丘(qiu)陵(ling)，地勢低矮(ai)，海拔大多(duo)在300米～500米之間，相對高差50米～150米，地勢由北向南傾斜，巖層近于(yu)水(shui)平，在流水(shui)的長期侵蝕(shi)切割作用下，形成臺階(jie)狀的方(fang)山(shan)丘(qiu)陵(ling)，南部多(duo)淺丘(qiu)，北部多(duo)深丘(qiu)。丘(qiu)陵(ling)地表軟硬相間的紫(zi)紅色(se)砂(sha)、頁(ye)巖極易風化為(wei)紫(zi)色(se)土，富含磷鉀，自(zi)然(ran)肥力較高，宜(yi)種性(xing)廣，是(shi)四(si)川(chuan)全省糧食(shi)、經濟作物主產(chan)區。
（3）華鎣山(shan)以(yi)東(dong)為(wei)盆(pen)東(dong)平(ping)行嶺(ling)(ling)谷(gu)區，由多(duo)條近東(dong)北(bei)西南走向的(de)條狀背斜(xie)山(shan)地(di)(di)與向斜(xie)寬谷(gu)組(zu)成(cheng)(cheng)，山(shan)地(di)(di)陡而窄，高(gao)700米-1000米，其(qi)中，華鎣山(shan)高(gao)1705米，為(wei)盆(pen)地(di)(di)底部最高(gao)峰。山(shan)地(di)(di)頂(ding)部的(de)石灰巖(yan)被雨水溶蝕后，常(chang)成(cheng)(cheng)凹槽(cao)，故山(shan)地(di)(di)大(da)多(duo)具(ju)有“一山(shan)二嶺(ling)(ling)一槽(cao)”或“一山(shan)三嶺(ling)(ling)二槽(cao)”的(de)特色。山(shan)嶺(ling)(ling)間(jian)的(de)谷(gu)地(di)(di)寬而緩，海(hai)拔(ba)300米～500米，其(qi)間(jian)丘陵、平(ping)壩交錯(cuo)分布，是平(ping)行嶺(ling)(ling)谷(gu)區工農業生產主要地(di)(di)區。
四川盆地邊(bian)緣山地區屬強烈上升的褶皺帶。
地(di)貌顯(xian)著特征是，海(hai)拔較高(gao)(gao)(gao)，過渡(du)性明顯(xian)，均(jun)為(wei)(wei)一(yi)系列中山(shan)(shan)(shan)和低山(shan)(shan)(shan)所(suo)圍繞。盆地(di)北緣(yuan)米倉山(shan)(shan)(shan)、大巴山(shan)(shan)(shan)近(jin)東(dong)西走向，是秦巴山(shan)(shan)(shan)地(di)南翼部(bu)分(fen)，海(hai)拔一(yi)般在1500米～2200米之間，山(shan)(shan)(shan)勢雄偉，山(shan)(shan)(shan)坡陡峭，溝谷深切，相對高(gao)(gao)(gao)差(cha)可(ke)達(da)(da)500米～1000米；南緣(yuan)大婁山(shan)(shan)(shan)屬氣勢磅礴的(de)云貴(gui)高(gao)(gao)(gao)原之一(yi)部(bu)分(fen)；西緣(yuan)有龍門山(shan)(shan)(shan)、邛崍山(shan)(shan)(shan)、峨眉山(shan)(shan)(shan)，山(shan)(shan)(shan)脊海(hai)拔都在1500米至～3000米以上，相對高(gao)(gao)(gao)差(cha)可(ke)達(da)(da)1000米，屬中國(guo)地(di)勢第(di)一(yi)級階梯。峨眉山(shan)(shan)(shan)頂峰高(gao)(gao)(gao)3099米，與附近(jin)的(de)平原相對高(gao)(gao)(gao)差(cha)達(da)(da)2660米，山(shan)(shan)(shan)勢巍峨秀麗，為(wei)(wei)中國(guo)四大佛(fo)教名(ming)山(shan)(shan)(shan)之一(yi)。
四(si)周為海拔2000～3000米的山(shan)(shan)(shan)脈和(he)高(gao)原(yuan)(yuan)所(suo)環繞，北面(mian)(mian)是大(da)巴山(shan)(shan)(shan)、米倉山(shan)(shan)(shan)、龍門山(shan)(shan)(shan)，西(xi)面(mian)(mian)是青藏高(gao)原(yuan)(yuan)邊緣的邛(qiong)崍山(shan)(shan)(shan)、大(da)涼山(shan)(shan)(shan)，南面(mian)(mian)是大(da)婁山(shan)(shan)(shan)，東面(mian)(mian)是巫山(shan)(shan)(shan)。
無論從構造(zao)還是人地(di)(di)(di)貌(mao)上看，四川(chuan)(chuan)盆(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)都是一(yi)(yi)個(ge)(ge)典型(xing)的盆(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)。它從震旦紀(ji)以來就(jiu)是地(di)(di)(di)殼比較穩定的大(da)(da)型(xing)拗(ao)陷(xian)區。晚三迭紀(ji)的印支運動(dong)(dong)中(zhong)(zhong)成(cheng)(cheng)為一(yi)(yi)個(ge)(ge)內(nei)陸湖盆(pen)(pen)(pen)(pen)(pen)，但范圍(wei)要比今日的四川(chuan)(chuan)大(da)(da)得多，中(zhong)(zhong)生代堆積了厚(hou)達3000～4000米的紫(zi)紅色(se)的砂巖和頁巖，因此人們又稱(cheng)它為“紅色(se)盆(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)”或(huo)“紫(zi)色(se)盆(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)”。中(zhong)(zhong)生代末期的四川(chuan)(chuan)運動(dong)(dong)使盆(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)周(zhou)圍(wei)褶皺成(cheng)(cheng)山(shan)(shan)，中(zhong)(zhong)間相對下(xia)陷(xian)，輪廓基(ji)本形成(cheng)(cheng)，盆(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)內(nei)部(bu)(bu)地(di)(di)(di)層也發(fa)生大(da)(da)規模的變形。東部(bu)(bu)出現(xian)一(yi)(yi)組北(bei)(bei)東向的褶皺，稱(cheng)盆(pen)(pen)(pen)(pen)(pen)東褶皺帶；中(zhong)(zhong)部(bu)(bu)形成(cheng)(cheng)穹(qiong)窿構造(zao)，稱(cheng)盆(pen)(pen)(pen)(pen)(pen)中(zhong)(zhong)穹(qiong)窿帶；西(xi)部(bu)(bu)表現(xian)成(cheng)(cheng)為盆(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)沉(chen)陷(xian)帶，為今天盆(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)的三個(ge)(ge)地(di)(di)(di)貌(mao)區奠定了基(ji)礎。新生代的喜馬(ma)拉雅運動(dong)(dong)使周(zhou)圍(wei)山(shan)(shan)地(di)(di)(di)再次上升，盆(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)再次相對下(xia)陷(xian)， 成(cheng)(cheng)都一(yi)(yi)帶下(xia)陷(xian)更深。同(tong)時，長(chang)江(jiang)切穿巫山(shan)(shan)，滾滾東流(liu)，完成(cheng)(cheng)了統一(yi)(yi)的長(chang)江(jiang)水系，使內(nei)流(liu)盆(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)轉(zhuan)變為外流(liu)盆(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)。四川(chuan)(chuan)盆(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)可明顯分(fen)為邊緣(yuan)山(shan)(shan)地(di)(di)(di)和盆(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)底部(bu)(bu)兩大(da)(da)部(bu)(bu)分(fen)，其(qi)面(mian)積分(fen)別約為10萬多和16萬多平(ping)方千米。 四川(chuan)(chuan)盆(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)是我國最大(da)(da)的外流(liu)盆(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)，面(mian)積26萬多平(ping)方千米。四川(chuan)(chuan)盆(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)內(nei)部(bu)(bu)丘陵、平(ping)原交錯，地(di)(di)(di)勢北(bei)(bei)高南低。由于地(di)(di)(di)表形態的不同(tong)，以華鎣山(shan)(shan)、龍泉(quan)山(shan)(shan)為界(jie)。
盆(pen)底可分為(wei)三部分：
①華鎣山以東為大致平行的(de)川東嶺谷(gu)，由東北—西南(nan)走向(xiang)的(de)許(xu)多條狀山體(ti)組成，海(hai)拔一般在(zai)700～800米，谷(gu)地(di)中(zhong)多低(di)丘與(yu)平壩，海(hai)拔200～500米，是川東農業和人口集中(zhong)的(de)地(di)方(fang)。
②華(hua)鎣山(shan)(shan)和(he)龍泉山(shan)(shan)之間為方山(shan)(shan)丘(qiu)(qiu)陵，即川中丘(qiu)(qiu)陵。區內由(you)于紫紅(hong)色(se)砂(sha)頁(ye)巖傾角平緩，受切割(ge)后形成大(da)片方山(shan)(shan)式丘(qiu)(qiu)陵。海拔350～450米(mi)，相(xiang)對高(gao)度幾十(shi)米(mi)。當地勞動人民利用方山(shan)(shan)山(shan)(shan)丘(qiu)(qiu)土層深厚的特點，把梯(ti)田一直修到山(shan)(shan)頂(ding)。
③龍(long)泉山以(yi)西(xi)為平原(yuan)。稱為川(chuan)西(xi)平原(yuan)或成(cheng)都(dou)平原(yuan)，面積6000多平方千米，是四川(chuan)盆(pen)地最大的平原(yuan)，也是西(xi)南地區最大的平原(yuan)，海拔約600米。
四(si)川(chuan)(chuan)盆(pen)(pen)(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)(di)(di)(di)(di)(di)屬揚(yang)子準地(di)(di)(di)(di)(di)(di)(di)(di)臺四(si)川(chuan)(chuan)臺坳(ao)。古生(sheng)代(dai)時相(xiang)對隆起(qi)，缺乏泥(ni)(ni)盆(pen)(pen)(pen)(pen)(pen)(pen)(pen)系(xi)和(he)石炭系(xi)。印支運(yun)動(dong)轉換(huan)為(wei)(wei)大型拗陷，晚燕山(shan)(shan)運(yun)動(dong)，特別是(shi)(shi)喜馬拉雅運(yun)動(dong)后發生(sheng)褶皺隆起(qi)。盆(pen)(pen)(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)(di)(di)(di)(di)(di)的(de)(de)(de)格(ge)局(ju)主要(yao)受北(bei)(bei)東(dong)—南(nan)(nan)(nan)西(xi)向(xiang)及北(bei)(bei)西(xi)向(xiang)兩條構造線控制，構成(cheng)(cheng)了典型的(de)(de)(de)菱形(xing)(xing)盆(pen)(pen)(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)(di)(di)(di)(di)(di)，四(si)川(chuan)(chuan)廣元、四(si)川(chuan)(chuan)雅安、四(si)川(chuan)(chuan)敘永為(wei)(wei)菱形(xing)(xing)的(de)(de)(de)四(si)頂(ding)點，東(dong)西(xi)兩邊稍長(chang)，為(wei)(wei)380～430公里(li)，南(nan)(nan)(nan)北(bei)(bei)兩邊略短(duan)，為(wei)(wei)310～330公里(li)。以上菱形(xing)(xing)四(si)頂(ding)點的(de)(de)(de)連線與(yu)盆(pen)(pen)(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)(di)(di)(di)(di)(di)內(nei)650～750米(mi)的(de)(de)(de)等(deng)(deng)高線大體相(xiang)當，盆(pen)(pen)(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)(di)(di)(di)(di)(di)底(di)部(bu)與(yu)邊緣(yuan)山(shan)(shan)地(di)(di)(di)(di)(di)(di)(di)(di)也以此為(wei)(wei)分(fen)界。四(si)川(chuan)(chuan)盆(pen)(pen)(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)(di)(di)(di)(di)(di)在距今(jin)1.4億年以前(qian)，還是(shi)(shi)內(nei)陸(lu)湖盆(pen)(pen)(pen)(pen)(pen)(pen)(pen)。至距今(jin)6.6千萬(wan)年時，盆(pen)(pen)(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)(di)(di)(di)(di)(di)邊緣(yuan)山(shan)(shan)地(di)(di)(di)(di)(di)(di)(di)(di)迅(xun)速隆升，長(chang)江中(zhong)(zhong)上游(you)水系(xi)開始溝通。盆(pen)(pen)(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)(di)(di)(di)(di)(di)內(nei)湖水東(dong)瀉奠定了現今(jin)之(zhi)地(di)(di)(di)(di)(di)(di)(di)(di)貌形(xing)(xing)態。盆(pen)(pen)(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)(di)(di)(di)(di)(di)邊緣(yuan)多(duo)(duo)低(di)山(shan)(shan)和(he)中(zhong)(zhong)山(shan)(shan)，山(shan)(shan)勢(shi)陡峻，發源盆(pen)(pen)(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)(di)(di)(di)(di)(di)邊緣(yuan)山(shan)(shan)地(di)(di)(di)(di)(di)(di)(di)(di)的(de)(de)(de)河(he)流大多(duo)(duo)為(wei)(wei)“V”型谷(gu)，嶺谷(gu)高差都逾(yu)500～1 000米(mi)， 地(di)(di)(di)(di)(di)(di)(di)(di)表(biao)崎嶇，故歷(li)史上就有(you)(you)“蜀道難，難于上青天”之(zhi)說。山(shan)(shan)脊海(hai)拔(ba)大多(duo)(duo)在2000～3000米(mi)，西(xi)北(bei)(bei)部(bu)與(yu)西(xi)部(bu)可超過(guo)3000～4000米(mi)，如龍門山(shan)(shan)4984米(mi)，峨眉(mei)山(shan)(shan)3099米(mi)，小相(xiang)嶺4 791米(mi)。地(di)(di)(di)(di)(di)(di)(di)(di)表(biao)廣泛(fan)出露古生(sheng)代(dai)及其以前(qian)的(de)(de)(de)石灰巖(yan)(yan)(yan)，其次(ci)為(wei)(wei)板巖(yan)(yan)(yan)、片巖(yan)(yan)(yan)、結晶灰巖(yan)(yan)(yan)、石英巖(yan)(yan)(yan)、砂(sha)泥(ni)(ni)巖(yan)(yan)(yan)和(he)礫巖(yan)(yan)(yan)，局(ju)部(bu)有(you)(you)花(hua)崗巖(yan)(yan)(yan)和(he)玄(xuan)武巖(yan)(yan)(yan)。石灰巖(yan)(yan)(yan)分(fen)布區可見(jian)石林、溶洞、暗河(he)、槽谷(gu)等(deng)(deng)喀(ka)斯特地(di)(di)(di)(di)(di)(di)(di)(di)貌，盆(pen)(pen)(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)(di)(di)(di)(di)(di)南(nan)(nan)(nan)緣(yuan)興文(wen)縣素有(you)(you)“石林洞鄉”之(zhi)稱（見(jian)興文(wen)石林）。巫(wu)山(shan)(shan)十二峰和(he)金佛山(shan)(shan)等(deng)(deng)名山(shan)(shan)主要(yao)也由石灰巖(yan)(yan)(yan)發育而成(cheng)(cheng)。由石灰巖(yan)(yan)(yan)、玄(xuan)武巖(yan)(yan)(yan)、花(hua)崗巖(yan)(yan)(yan)等(deng)(deng)組成(cheng)(cheng)的(de)(de)(de)峨眉(mei)山(shan)(shan)及由砂(sha)泥(ni)(ni)巖(yan)(yan)(yan)、礫巖(yan)(yan)(yan)組成(cheng)(cheng)的(de)(de)(de)青城山(shan)(shan)，素有(you)(you)“峨眉(mei)天下秀”、“青城天下幽”之(zhi)稱，為(wei)(wei)中(zhong)(zhong)國著(zhu)名游(you)覽勝地(di)(di)(di)(di)(di)(di)(di)(di)。盆(pen)(pen)(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)(di)(di)(di)(di)(di)底(di)部(bu)海(hai)拔(ba)多(duo)(duo)數在250～700米(mi)，地(di)(di)(di)(di)(di)(di)(di)(di)勢(shi)東(dong)南(nan)(nan)(nan)傾，盆(pen)(pen)(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)(di)(di)(di)(di)(di)內(nei)各(ge)河(he)流均由邊緣(yuan)山(shan)(shan)地(di)(di)(di)(di)(di)(di)(di)(di)匯(hui)聚盆(pen)(pen)(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)(di)(di)(di)(di)(di)底(di)部(bu)的(de)(de)(de)長(chang)江干流，形(xing)(xing)成(cheng)(cheng)向(xiang)心狀水系(xi)。地(di)(di)(di)(di)(di)(di)(di)(di)表(biao)為(wei)(wei)大面積的(de)(de)(de)中(zhong)(zhong)生(sheng)代(dai)紫紅(hong)(hong)色砂(sha)巖(yan)(yan)(yan)與(yu)泥(ni)(ni)巖(yan)(yan)(yan)所覆(fu)蓋，故稱為(wei)(wei)“紅(hong)(hong)層盆(pen)(pen)(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)(di)(di)(di)(di)(di)”，是(shi)(shi)中(zhong)(zhong)國中(zhong)(zhong)生(sheng)代(dai)陸(lu)相(xiang)紅(hong)(hong)層分(fen)布最集中(zhong)(zhong)地(di)(di)(di)(di)(di)(di)(di)(di)區。四(si)川(chuan)(chuan)盆(pen)(pen)(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)(di)(di)(di)(di)(di)為(wei)(wei)丘陵性(xing)盆(pen)(pen)(pen)(pen)(pen)(pen)(pen)地(di)(di)(di)(di)(di)(di)(di)(di)，底(di)部(bu)以丘陵為(wei)(wei)主，次(ci)為(wei)(wei)低(di)山(shan)(shan)和(he)平原。
四川盆地(di)屬揚子(zi)陸(lu)臺(tai)一(yi)部分(fen)，稱為四川陸(lu)臺(tai)，屬較穩定的(de)地(di)區(qu)，但仍經(jing)過兩次(ci)大規模的(de)海浸。第一(yi)次(ci)從5億多(duo)年(nian)前(qian)的(de)寒武紀(ji)(ji)開始，延續(xu)到3.7億多(duo)年(nian)的(de)志留紀(ji)(ji)，不斷下陷(xian)成了海洋盆地(di)，志留紀(ji)(ji)時(shi)發(fa)生加里東運動，除了西(xi)部的(de)龍門山(shan)地(di)槽(cao)繼續(xu)下陷(xian)外，其余(yu)地(di)區(qu)上升為陸(lu)。2.7億年(nian)前(qian)的(de)石炭(tan)紀(ji)(ji)末(mo)，發(fa)生范圍(wei)更大的(de)第二(er)次(ci)海浸，盆地(di)再次(ci)為海洋占據。二(er)疊紀(ji)(ji)時(shi)海陸(lu)交替，形成重慶附(fu)近(jin)的(de)南酮、松藻、天(tian)府等煤礦(kuang)。二(er)疊紀(ji)(ji)末(mo)，盆地(di)西(xi)部巖漿噴出，峨眉山(shan)小金頂及清音閣一(yi)帶(dai)的(de)玄武巖就在這(zhe)時(shi)生成。
距今(jin)1.9億年的(de)三疊(die)紀，“印支運動(dong)”使(shi)盆(pen)地(di)(di)邊(bian)緣(yuan)逐漸隆起(qi)成山，被海(hai)水(shui)淹沒的(de)地(di)(di)區(qu)(qu)逐漸上(shang)升成陸(lu)，由海(hai)盆(pen)轉為湖(hu)盆(pen)。當時湖(hu)水(shui)幾乎占據現今(jin)四川(chuan)盆(pen)地(di)(di)的(de)全境，稱為“蜀湖(hu)”，從此結(jie)束(shu)了海(hai)浸的(de)歷史。在(zai)中生(sheng)代漫長(chang)的(de)1億多年里，盆(pen)地(di)(di)氣候溫暖濕潤，到處生(sheng)長(chang)蕨類、蘇(su)鐵和(he)裸子植物，是又一(yi)個成煤期，永榮煤礦(kuang)即在(zai)三疊(die)紀和(he)侏羅紀時形成。東起(qi)長(chang)壽(shou)、墊江，西到江油、邛崍，北抵大巴山麓(lu)，南到貴州(zhou)(zhou)赤(chi)水(shui)，還是天然氣富集區(qu)(qu)。這一(yi)時期爬行動(dong)物恐龍稱霸一(yi)時。1957年在(zai)合州(zhou)(zhou)發(fa)現的(de)“合州(zhou)(zhou)馬(ma)門(men)溪(xi)龍”身長(chang)22米，高3.5米，是中國亞(ya)洲最大和(he)最完(wan)整的(de)恐龍化石。
7000萬(wan)年前的(de)(de)(de)(de)白堊紀(ji)末期，發生(sheng)又一(yi)次(ci)強(qiang)烈的(de)(de)(de)(de)地(di)殼運動“燕山(shan)運動”。盆(pen)(pen)地(di)四(si)周山(shan)地(di)繼續隆起，同時(shi)(shi)產生(sheng)不少大(da)(da)斷層(ceng)(ceng)，如(ru)西(xi)部的(de)(de)(de)(de)龍門山(shan)大(da)(da)斷層(ceng)(ceng)和東部的(de)(de)(de)(de)華瑩山(shan)大(da)(da)斷層(ceng)(ceng)，把盆(pen)(pen)地(di)分(fen)(fen)為(wei)三部分(fen)(fen)。蜀湖縮(suo)(suo)小為(wei)僅(jin)有2萬(wan)平方公里(li)的(de)(de)(de)(de)蜀湖。封(feng)閉的(de)(de)(de)(de)盆(pen)(pen)地(di)地(di)形(xing)及急劇縮(suo)(suo)小的(de)(de)(de)(de)水面，使氣候逐漸變(bian)得(de)干(gan)熱，沉積物由(you)(you)(you)海相(xiang)、海陸交替相(xiang)變(bian)為(wei)陸相(xiang)，大(da)(da)量風化、侵(qin)蝕(shi)、剝蝕(shi)的(de)(de)(de)(de)物質(zhi)(zhi)在盆(pen)(pen)地(di)堆積了(le)(le)數(shu)千(qian)米厚，形(xing)成紅(hong)色(se)和紫紅(hong)色(se)的(de)(de)(de)(de)砂、泥、頁巖。裸子植物不斷衰退，恐龍滅絕了(le)(le)。內陸湖泊(bo)在干(gan)燥條(tiao)件下，經(jing)強(qiang)烈蒸發，濃度增大(da)(da)，鹽(yan)分(fen)(fen)不斷積累(lei)，形(xing)成鹽(yan)湖，后來泥沙掩埋而保存于地(di)層(ceng)(ceng)之(zhi)中，經(jing)過漫長的(de)(de)(de)(de)地(di)質(zhi)(zhi)作用形(xing)成巖層(ceng)(ceng)，自貢一(yi)帶是(shi)著名的(de)(de)(de)(de)井鹽(yan)產地(di)。 2000多(duo)萬(wan)年前的(de)(de)(de)(de)新第(di)三紀(ji)，受喜馬拉(la)雅造山(shan)運動的(de)(de)(de)(de)影響。距今二、三百萬(wan)年的(de)(de)(de)(de)第(di)四(si)紀(ji)，地(di)殼再(zai)次(ci)發生(sheng)構造運動。從而，四(si)川盆(pen)(pen)地(di)由(you)(you)(you)內流(liu)(liu)盆(pen)(pen)地(di)變(bian)為(wei)外(wai)流(liu)(liu)陸盆(pen)(pen)，由(you)(you)(you)封(feng)閉的(de)(de)(de)(de)內流(liu)(liu)區(qu)(qu)變(bian)為(wei)外(wai)流(liu)(liu)區(qu)(qu)，由(you)(you)(you)以堆積為(wei)主變(bian)為(wei)侵(qin)蝕(shi)為(wei)主，經(jing)歷了(le)(le)海盆(pen)(pen)——湖盆(pen)(pen)——陸盆(pen)(pen)的(de)(de)(de)(de)滄桑之(zhi)變(bian)。 第(di)四(si)紀(ji)是(shi)冰川廣(guang)布的(de)(de)(de)(de)時(shi)(shi)代，盆(pen)(pen)地(di)西(xi)北山(shan)地(di)發育大(da)(da)量冰川。冰川消融后，大(da)(da)量沉積物由(you)(you)(you)岷(min)江(jiang)、沱江(jiang)等(deng)攜(xie)帶，堆積在西(xi)部的(de)(de)(de)(de)凹陷區(qu)(qu)，即(ji)以前的(de)(de)(de)(de)蜀湖之(zhi)中，最終形(xing)成了(le)(le)成都平原。 四(si)川盆(pen)(pen)地(di)地(di)貌豐富，平原7%，丘(qiu)陵52%，低山(shan)41%。
四(si)川(chuan)(chuan)盆(pen)(pen)(pen)地(di)(di)(di)中(zhong)(zhong)植物近(jin)萬種(zhong)，古老而特有(you)(you)種(zhong)之多為中(zhong)(zhong)國其他地(di)(di)(di)區所不及。在(zai)盆(pen)(pen)(pen)地(di)(di)(di)邊(bian)緣(yuan)(yuan)山(shan)地(di)(di)(di)及盆(pen)(pen)(pen)東平行嶺(ling)谷尚(shang)可見(jian)(jian)水(shui)杉、銀杉、鵝(e)掌楸、檫木、三尖杉、珙桐、水(shui)青樹(shu)、連(lian)香樹(shu)、領春木、金錢槭、蠟梅、杜仲、紅豆杉、鐘萼木、福建柏(bo)、穗花杉、崖柏(bo)、木瓜紅等珍稀(xi)孑(jie)遺(yi)植物與特有(you)(you)種(zhong)。在(zai)濕熱(re)河谷可見(jian)(jian)桫欏(luo)、小羽桫欏(luo)、烏毛(mao)蕨、華(hua)南(nan)紫萁、里(li)白等古熱(re)帶(dai)孑(jie)遺(yi)植物。 四(si)川(chuan)(chuan)盆(pen)(pen)(pen)地(di)(di)(di)的地(di)(di)(di)帶(dai)性植被是(shi)亞(ya)(ya)熱(re)帶(dai)常(chang)綠(lv)闊葉(xie)林(lin)，其代表樹(shu)種(zhong)有(you)(you)栲樹(shu)、峨眉栲、刺果米櫧、青岡、曼青岡、包(bao)石(shi)櫟(li)、華(hua)木荷、大(da)包(bao)木荷、四(si)川(chuan)(chuan)大(da)頭茶、楨楠(nan)、潤(run)楠(nan)等，海拔(ba)一(yi)般(ban)情(qing)況(kuang)下(xia)在(zai)1600～1 800米以下(xia)。其次(ci)有(you)(you)馬(ma)尾松、杉木、柏(bo)木組成(cheng) 的亞(ya)(ya)熱(re)帶(dai)針(zhen)(zhen)葉(xie)林(lin)及竹(zhu)林(lin)。 邊(bian)緣(yuan)(yuan)山(shan)地(di)(di)(di)從下(xia)而上是(shi)常(chang)綠(lv)闊葉(xie)林(lin)、常(chang)綠(lv)闊葉(xie)與落葉(xie)闊葉(xie)混交林(lin)，寒(han)溫帶(dai)山(shan)地(di)(di)(di)針(zhen)(zhen)葉(xie)林(lin)，局(ju)部有(you)(you)亞(ya)(ya)高山(shan)灌叢草甸。
四川盆(pen)(pen)(pen)(pen)(pen)地(di)是(shi)中(zhong)(zhong)(zhong)(zhong)國動(dong)(dong)(dong)物(wu)種類最(zui)(zui)多(duo)、最(zui)(zui)齊全(quan)(quan)的(de)(de)地(di)區(qu)之(zhi)一(yi)。據統計(ji)，除魚類外(wai)，盆(pen)(pen)(pen)(pen)(pen)地(di)底部共有動(dong)(dong)(dong)物(wu)417種，盆(pen)(pen)(pen)(pen)(pen)地(di)西(xi)(xi)(xi)緣(yuan)、北緣(yuan)和(he)南(nan)緣(yuan)山地(di)分別為487種、317種與(yu)288種，其中(zhong)(zhong)(zhong)(zhong)經(jing)濟(ji)動(dong)(dong)(dong)物(wu)均(jun)占一(yi)半(ban)以(yi)上。盆(pen)(pen)(pen)(pen)(pen)地(di)西(xi)(xi)(xi)緣(yuan)山地(di)是(shi)中(zhong)(zhong)(zhong)(zhong)國特有而古老動(dong)(dong)(dong)物(wu)保存(cun)最(zui)(zui)好、最(zui)(zui)集中(zhong)(zhong)(zhong)(zhong)的(de)(de)地(di)區(qu)，屬于一(yi)類保護(hu)(hu)動(dong)(dong)(dong)物(wu)的(de)(de)有大熊貓、金絲猴(hou)、扭角(jiao)羚(ling)、灰(hui)金絲猴(hou)、白(bai)唇鹿等(deng)(deng)。還有珍貴特有動(dong)(dong)(dong)物(wu)小(xiao)熊貓、雪豹、鬣羚(ling)、短尾(wei)猴(hou)、獼猴(hou)、毛(mao)冠鹿、水(shui)獺(ta)及鴛鴦、血雉、紅腹(fu)角(jiao)雉、綠尾(wei)虹雉、白(bai)腹(fu)錦雞、紅腹(fu)錦雞等(deng)(deng)。 盆(pen)(pen)(pen)(pen)(pen)地(di)西(xi)(xi)(xi)緣(yuan)的(de)(de)平武、青川、北川、寶興、天(tian)全(quan)(quan)、洪雅、馬(ma)(ma)邊等(deng)(deng)地(di)，均(jun)為中(zhong)(zhong)(zhong)(zhong)國大熊貓的(de)(de)主要分布區(qu)。已設立唐(tang)家河(he)、王朗(lang)、臥龍（見臥龍自然保護(hu)(hu)區(qu)）、蜂桶寨、喇(la)叭河(he)等(deng)(deng)7處大熊貓、金絲猴(hou)等(deng)(deng)自然保護(hu)(hu)區(qu)。 酉陽(yang)、馬(ma)(ma)邊、平武等(deng)(deng)盆(pen)(pen)(pen)(pen)(pen)地(di)邊緣(yuan)山地(di)溪溝(gou)中(zhong)(zhong)(zhong)(zhong)的(de)(de)大鯢(ni)及長江、金沙(sha)江中(zhong)(zhong)(zhong)(zhong)的(de)(de)中(zhong)(zhong)(zhong)(zhong)華鱘、白(bai)鱘也為四川所特有，均(jun)屬國家保護(hu)(hu)動(dong)(dong)(dong)物(wu)。
四川(chuan)盆地有煤、鐵、天然(ran)(ran)氣(qi)、石(shi)油、鹽(yan)、芒(mang)硝、石(shi)膏、磷、硫、鋁、金、銅(tong)、錳、石(shi)墨、汞等礦產資源，其中(zhong)天然(ran)(ran)氣(qi)、芒(mang)硝為全中(zhong)國(guo)之冠，并有中(zhong)國(guo)重(zhong)要的(de)鍶礦。川(chuan)東(dong)北是世界最大的(de)天然(ran)(ran)氣(qi)富(fu)集區之一(yi)，川(chuan)中(zhong)和南(nan)充等地鹽(yan)巖礦儲(chu)量很大。
四(si)川盆地地形閉塞，由于(yu)北部秦嶺阻擋冷空氣，冬(dong)季(ji)氣溫(wen)高(gao)于(yu)同(tong)緯度(du)其(qi)他地區。最冷月北部均(jun)溫(wen)3～5℃，南部5~8℃，較(jiao)(jiao)同(tong)緯度(du)的(de)上(shang)(shang)(shang)海、湖(hu)北、安徽及緯度(du)偏南的(de)貴州高(gao)1～4℃。盆地北部極(ji)端最低(di)溫(wen)-8～-5℃，南部-5℃~-2℃。霜(shuang)雪少見，年無(wu)霜(shuang)期長(chang)(chang)280～350天，同(tong)緯度(du)上(shang)(shang)(shang)的(de)武(wu)漢(han)冬(dong)天卻霜(shuang)雪不斷(duan)，盆地位于(yu)長(chang)(chang)江河(he)谷中的(de)長(chang)(chang)寧全年無(wu)霜(shuang)。 盆地各地夏季(ji)始于(yu)5月底，終于(yu)9月中旬，夏長(chang)(chang)4個月，溫(wen)度(du)上(shang)(shang)(shang)東高(gao)西低(di)。盆地西部夏天平均(jun)氣溫(wen)約(yue)25℃，較(jiao)(jiao)同(tong)緯度(du)的(de)上(shang)(shang)(shang)海、武(wu)漢(han)等城市偏低(di)3-4度(du)，但(dan)濕度(du)較(jiao)(jiao)大(da)，所以(yi)悶熱難忍。
東(dong)部(bu)最熱(re)月(yue)氣(qi)(qi)溫(wen)(wen)(wen)高(gao)(gao)(gao)達(da)26～29℃，長(chang)江河谷(gu)局(ju)地(di)達(da)到(dao)30℃。盛夏(xia)連晴高(gao)(gao)(gao)溫(wen)(wen)(wen)天氣(qi)(qi)又造成盆(pen)(pen)地(di)東(dong)南部(bu)嚴重的夏(xia)伏旱。盆(pen)(pen)地(di)氣(qi)(qi)溫(wen)(wen)(wen)東(dong)南高(gao)(gao)(gao)西(xi)北低，盆(pen)(pen)底(di)高(gao)(gao)(gao)邊緣(yuan)(yuan)低； 各地(di)年均溫(wen)(wen)(wen)16～18℃。10℃以上(shang)活動(dong)(dong)積(ji)溫(wen)(wen)(wen)4500～6000℃，持續期8～9個月(yue)，屬中亞熱(re)帶(dai)。東(dong)南部(bu)的長(chang)江河谷(gu)積(ji)溫(wen)(wen)(wen)超過6000℃，相當于中國(guo)南嶺以南的南亞熱(re)帶(dai)氣(qi)(qi)候。盆(pen)(pen)地(di)氣(qi)(qi)溫(wen)(wen)(wen)東(dong)高(gao)(gao)(gao)西(xi)低，南高(gao)(gao)(gao)北低，盆(pen)(pen)底(di)高(gao)(gao)(gao)而邊緣(yuan)(yuan)低，等溫(wen)(wen)(wen)線(xian)分布(bu)呈現同心圓狀。盆(pen)(pen)地(di)邊緣(yuan)(yuan)山地(di)氣(qi)(qi)溫(wen)(wen)(wen)具有垂直分布(bu)特點，如峨眉山、金佛山海拔升高(gao)(gao)(gao)百米，氣(qi)(qi)溫(wen)(wen)(wen)遞減0.55℃和0.61℃。峨眉山頂年均溫(wen)(wen)(wen)僅3℃，10℃以上(shang)活動(dong)(dong)積(ji)溫(wen)(wen)(wen)586℃，氣(qi)(qi)候上(shang)相當于寒溫(wen)(wen)(wen)帶(dai)和亞寒帶(dai)。
四川盆地(di)(di)年降(jiang)水(shui)量1000～1300毫(hao)米(mi)，盆地(di)(di)邊緣山(shan)地(di)(di)降(jiang)水(shui)十分充沛(pei)，如樂(le)山(shan)和雅(ya)安間的西緣山(shan)地(di)(di)年降(jiang)水(shui)量為1 500～1800毫(hao)米(mi)，為中國(guo)突出的多雨區，有(you)“華西雨屏”之(zhi)(zhi)稱。但冬干、春旱、夏澇、秋綿雨，年內(nei)分配不均，70～75%的雨量集(ji)中于6～10月。最(zui)大(da)(da)日(ri)降(jiang)水(shui)量可達(da)300～500毫(hao)米(mi)。“巴山(shan)夜雨”自古聞名，夜雨占總雨量的60～70%以上(shang)。盆地(di)(di)區霧大(da)(da)濕(shi)重，云低(di)陰(yin)天多。峨(e)眉山(shan)、金佛山(shan)是中國(guo)霧日(ri)最(zui)多地(di)(di)區之(zhi)(zhi)一，年相對濕(shi)度之(zhi)(zhi)高也為中國(guo)之(zhi)(zhi)冠。盆地(di)(di)年日(ri)照僅900～1300小(xiao)時，年太陽輻射量為370～420千焦耳/平方厘米(mi)，均為中國(guo)最(zui)低(di)值，故有(you)“蜀犬吠日(ri)”之(zhi)(zhi)說。
